One possible method for fuel injection in gasoline engines is intake manifold injection, which is being increasingly replaced by direct fuel injection. The latter method results in much better fuel distribution in the combustion chambers, and, thus, in an improved power yield with lower fuel consumption.
In addition, there are also gasoline engines with a combination of intake manifold injection and direct injection, a so-called dual system. This is advantageous in particular in light of increasingly stringent emission requirements and emission limits, since intake manifold injection, for example at medium load ranges, results in better emission values than does direct injection. In contrast, in the full load range, direct injection allows a reduction in so-called knocking, for example.
To improve a response characteristic of a turbocharger, within the scope of so-called “scavenging,” an intake valve and an exhaust valve of a combustion chamber can be opened simultaneously to obtain higher flow values in the exhaust pipe and thus in the turbocharger. Such a method for an internal combustion engine with intake manifold operation is known from DE 10 2009 028 798 A1, for example.
A method is known from EP 2 781 726 A1, for example, for reducing, in a dual system, a flush rate of fuel during the simultaneous opening of an intake valve and an exhaust valve. For this purpose, a period of time during which both valves are open and a fuel quantity that is introduced via intake manifold injection are changed based on a fuel quantity that is introduced via direct injection.
A method is also known from EP 2 787 203 A1, for example, for reducing, in a dual system, a flush rate of fuel during the simultaneous opening of an intake valve and an exhaust valve. For this purpose, the injection times for both types of injection are set to a time after the exhaust valve has closed.